Recently, portable information technology (IT) products such as smartphones, wearable devices, and the like, have been thinned. Therefore, the necessity of thinning a passive element in order to decrease an overall thickness of a package has increased.
To this end, demand for a thin-film ceramic capacitor capable of implementing a reduced thickness of a package, as compared to a multilayer ceramic capacitor, has also increased.
Meanwhile, in developing a capacitor, as research into a dielectric material has been conducted, PbZrTiO3 (PZT)-based dielectric materials and BaTiO3 (BT)-based dielectric materials have been spotlighted. The PZT-based and BT-based dielectric materials have high permittivity, a low dielectric loss, and excellent electrical properties.
However, in these PZT-based and BT-based dielectric materials, changes in dielectric properties depending on a temperature are large due to ferroelectricity, such that these PZT-based and BT-based dielectric materials have high temperature-dependency. As a result, electrical properties of a manufactured device may be changed depending on a use temperature, such that performance thereof may be changed depending on a temperature.
Due to this temperature instability problem, research into application of a paraelectric material capable of solving this problem has been conducted. However, since the paraelectric material such as BaSrTiO3 (BST) has a relatively low dielectric constant as compared to the ferroelectric material, there is a limitation in manufacturing a high-capacitance capacitor.
Therefore, there is a need to develop a method of utilizing a ferroelectric material stable against a temperature change and has high permittivity as a material of a capacitor.